Lehnerite is a rare secondary phosphate mineral typically found as small, vibrant yellow tabular crystals within weathered pegmatite deposits. It is specifically recognized for its occurrence in phosphate-rich zones of granite pegmatites and requires careful handling due to its uranium content.

Hardness

2-3

Mohs

Luster

Vitreous to resinous

Streak

Pale yellow

Transparency

Transparent to translucent

mineralrareVivianite Group family

Lehnerite

Hardness: 2-3
Luster: Vitreous to resinous
Streak: Pale yellow
Transparency: Transparent to translucent

Is this lehnerite?

5-step field check

Run through these checks against the specimen in your hand. The more boxes tick, the more confident the ID.

1
Test the hardness
Try to scratch lehnerite with a known reference. Lehnerite sits at Mohs 2-3, softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Streak: pale yellow.
3
Read the luster
Hold the specimen under a strong light. Luster: vitreous to resinous.
4
Match the color range
Compare against the expected color range: bronze, honey yellow.
5
Look at form & habit
Crystal system: monoclinic. Typical habit: tabular crystals, radial aggregates.

Often confused with

Lehnerite vs. its common look-alikes, and how to tell them apart in the field.

How to tell apart: Streak differs, so Lehnerite leaves pale yellow, Saléeite leaves yellow white; luster reads vitreous to resinous on Lehnerite and adamantine to waxy on Saléeite.

Compare →

Often found alongside lehnerite

Minerals reported to co-occur with lehnerite. Spotting these in float or country rock is a strong cue you are in the right ground.

All properties

Chemical formula: Mn²⁺(UO₂)₂(PO₄)₂·8H₂O
Mohs hardness: 2-3
Density: 3.5-3.6 g/cm³
Colors: Bronze Honey yellow
Streak: Pale yellow
Luster: Vitreous to resinous
Transparency: Transparent to translucent
Crystal system: Monoclinic
Crystal habit: Tabular crystals, radial aggregates
Cleavage: Perfect on {010}; good on {101}; less good on {101}; poor on {100}
Rarity: Rare
Uses: Collector
Host rock: A rare secondary mineral in the oxidized zone of a complex granite pegmatite

Where rockhounds find lehnerite

Classic worldwide localities

Hagendorf, Bavaria, Germany

Field-hunting tip

Where it forms: A rare secondary mineral in the oxidized zone of a complex granite pegmatite. If you start seeing zwieselite, rockbridgeite in float, you are in the right ground. Typical habit: tabular crystals, radial aggregates. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify lehnerite?+

Mohs hardness is 2-3. Luster: vitreous to resinous. The streak is pale yellow. Common colors include bronze, honey yellow.

Where is lehnerite found?+

Notable localities include Hagendorf, Bavaria, Germany.

Is lehnerite safe to handle?+

Lehnerite contains uranium or thorium and calls for real care. Contains uranium; handle with care and wash hands thoroughly after handling. Store in a labeled, shielded container away from living areas.

What rocks look like lehnerite?+

Lehnerite is most often confused with Autunite, Torbernite, Saléeite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with lehnerite?+

Lehnerite commonly co-occurs with Zwieselite, Rockbridgeite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does lehnerite form in?+

Where it forms: A rare secondary mineral in the oxidized zone of a complex granite pegmatite. Working float back to the host body is the standard way to chase a fresh occurrence.

What is lehnerite used for?+

Lehnerite is used in collector.

Find lehnerite on the map

RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.